Liquid Structure of Ionic Liquids with [NTf2]- Anions, Derived from Neutron Scattering.

The liquid structure of three common ionic liquids (ILs) was investigated by neutron scattering for the first time. The ILs were based on the bis(trifluoromethanesulfonyl)imide anion, abbreviated in the literature as [NTf2]- or [TFSI]-, and on the following cations: 1-ethyl-3-methylimidazolium, [C2mim]+; 1-decyl-3-methylimidazolium, [C10mim]+; and trihexyl(tetradecyl)phosphonium, [P666,14]+. Comparative analysis of the three ILs confirmed increased size of nonpolar nanodomains with increasing bulk of alkyl chains. It also sheds light on the cation-anion interactions, providing experimental insight into strength, directionality, and angle of hydrogen bonds between protons on the imidazolium ring, as well as H-C-P protons in [P666,14]+, to oxygen and nitrogen atoms in the [NTf2]-. The new Dissolve data analysis package enabled, for the first time, the analysis of neutron scattering data of ILs with long alkyl chains, in particular, of [P666,14][NTf2]. Results generated with Dissolve were validated by comparing outputs from three different models, starting from three different sets of cation charges, for each of the three ILs, which gave convergent outcomes. Finally, a modified method for the synthesis of perdeuterated [P666,14][NTf2] has been reported, with the aim of reporting a complete set of synthetic and data processing approaches, laying robust foundations that enable the study of the phosphonium ILs family by neutron scattering.

A High-Throughput Experimental Approach to Screening Gas Sorption by Liquids and Solids.

High-precision measurement of gas uptake from single or mixed feeds in solid and liquid sorbents traditionally requires time-consuming experimental procedures and/or complex and costly equipment. A simple and cost-effective headspace gas chromatography (HS-GC) approach for the fast, universal experimental screening of sorbents for gas uptake and/or determination of their real gas separation selectivity has been developed and is demonstrated for pressures up to 2500 mbar and temperatures above 30 °C. This method allows screening of solids and both volatile and nonvolatile liquid materials, physisorbents, and chemisorbents using both single and mixed permanent gases that can include CO2, CH4, H2, and NH3, for gas uptakes as low as 0.04 mmol or 1.8 mg of CO2. We estimate that this method allows for the screening of at least 30-96 sorbents (in triplicate) or 90-264 sorbents (singles) per day, representing at least a 90-3000 times reduction in the time required for equivalent analysis.

Insights into the Absorption of Hydrocarbon Gases in Phosphorus-Containing Ionic Liquids.

The solubility of ethane, ethylene, propane, and propylene was measured in two phosphorus-containing ionic liquids, trihexyltetradecylphosphonium bis(2,4,4-trimethylpentyl)phosphinate, [P6,6,6,14][DiOP], and 1-butyl-3-methylimidazolium dimethylphosphate, [C4C1Im][DMP], using an isochoric saturation method. The ionic liquid [C4C1Im][DMP] absorbed between 1 and 20 molecules of gas per 1000 ion pairs, at 313 K and 0.1 MPa, while [P6,6,6,14][DiOP] absorbed up to 169 molecules of propane per 1000 ion pairs under the same conditions. [C4C1Im][DMP] had a higher capacity to absorb olefins than paraffins, while the opposite was true for [P6,6,6,14][DiOP], with the former being slightly more selective than the later. From the analysis of the thermodynamic properties of solvation, we concluded that in both ionic liquids and for all of the studied gases the solvation is ruled by the entropy, even if its contribution is unfavorable. These results, together with density measurements, 2D NMR studies, and self-diffusion coefficients suggest that the gases' solubility is ruled mostly by nonspecific interactions with the ionic liquids and that the looser ion packing in [P6,6,6,14][DiOP] makes it easier to accommodate the gases compared to [C4C1Im][DMP].

Mitochondrial Sirtuin TcSir2rp3 Affects TcSODA Activity and Oxidative Stress Response in Trypanosoma cruzi.

Trypanosoma cruzi faces a variety of environmental scenarios during its life cycle, which include changes in the redox environment that requires a fine regulation of a complex antioxidant arsenal of enzymes. Reversible posttranslational modifications, as lysine acetylation, are a fast and economical way for cells to react to environmental conditions. Recently, we found that the main antioxidant enzymes, including the mitochondrial superoxide dismutase A (TcSODA) are acetylated in T. cruzi, suggesting that protein acetylation could participate in the oxidative stress response in T. cruzi. Therefore, we investigated whether mitochondrial lysine deacetylase TcSir2rp3 was involved in the activity control of TcSODA. We observed an increased resistance to hydrogen peroxide and menadione in parasites overexpressing TcSir2rp3. Increased resistance was also found for benznidazole and nifurtimox, known to induce reactive oxidative and nitrosactive species in the parasite, associated to that a reduction in the ROS levels was observed. To better understand the way TcSir2rp3 could contributes to oxidative stress response, we analyzed the expression of TcSODA in the TcSir2rp3 overexpressing parasites and did not detect any increase in protein levels of this enzyme. However, we found that these parasites presented higher levels of superoxide dismutase activity, and also that TcSir2rp3 and TcSODA interacts in vivo. Knowing that TcSODA is acetylated at lysine residues K44 and K97, and that K97 is located at a similar region in the protein structure as K68 in human manganese superoxide dismutase (MnSOD), responsible for regulating MnSOD activity, we generated mutated versions of TcSODA at K44 and K97 and found that replacing K97 by glutamine, which mimics an acetylated lysine, negatively affects the enzyme activity in vitro. By using molecular dynamics approaches, we revealed that acetylation of K97 induces specific conformational changes in TcSODA with respect to hydrogen-bonding pattern to neighbor residues, suggesting a key participation of this residue to modulate the affinity to O2- . Taken together, our results showed for the first time the involvement of lysine acetylation in the maintenance of homeostatic redox state in trypanosomatids, contributing to the understanding of mechanisms used by T. cruzi to progress during the infection.

Os pais como pilares para a segurança do paciente em unidade neonatal / Parents as pillars for patient safety in a neonatal unit / Padres como pilares para la seguridad del paciente em una unidad neonatal

Objetivo: conhecer a experiência dos pais como estratégia de avaliação da qualidade da assistência de enfermagem. Método: pesquisa descritiva com abordagem qualitativa, desenvolvida na Unidade Neonatal de um Hospital do sul do Brasil. A coleta de dados foi realizada através de entrevistas, utilizando a técnica do incidente crítico (TIC), com 18 pais que estavam com seus filhos internados por 20 dias ou mais e que tinham previsão e plano de alta hospitalar. Após, os dados foram submetidos à análise de conteúdo. Resultados: a análise revelou fragilidades no cuidado prestado pela equipe de enfermagem em relação à administração de medicamentos, ao uso de equipamentos, à monitorização e ao posicionamento dos bebês, aos cuidados com a pele e à higiene de mãos. Conclusão: a experiência dos pais revelou elementos que integram a avaliação da assistência em enfermagem, destacando-os como pilares para a segurança do paciente.

Objective: to learn the parents' experience as a strategy for assessing the quality of nursing care. Method: in this qualitative, descriptive study at the Neonatal Unit of a hospital in southern Brazil, data were collected by critical incident (CI) interviews of 18 parents whose children had been hospitalized for 20 days or more, and whose discharge was scheduled and planned for. The data subsequently underwent content analysis. Results: data analysis revealed weaknesses in the care provided by the nursing staff as regards administration of medication, use of equipment, monitoring and positioning of babies, skin care and hand hygiene. Conclusion: The parents' experience revealed elements that enter into evaluation of nursing care, revealing parents to be mainstays of patient safety.

Objetivo: conocer la experiencia de los padres como estrategia para evaluar la calidad de la atención de enfermería. Método: en este estudio cualitativo y descriptivo en la Unidad Neonatal de un hospital en el sur de Brasil, los datos fueron recolectados por entrevistas de incidentes críticos (IC) de 18 padres cuyos hijos habían estado hospitalizados durante 20 días o más, y cuyo alta fue programada y planificada para. Los datos posteriormente se sometieron a análisis de contenido. Resultados: el análisis de datos reveló debilidades en la atención brindada por el personal de enfermería en lo que respecta a la administración de medicamentos, uso de equipos, monitoreo y posicionamiento de bebés, cuidado de la piel e higiene de manos. Conclusión: la experiencia de los padres reveló elementos que entran en la evaluación de la atención de enfermería, revelando que los padres son pilares de la seguridad del paciente.

Hydration of sulfobetaine dizwitterions as a function of alkyl spacer length.

The solvation and structure of bolaform dizwitterions containing two sulfobetaine moieties in concentrated aqueous solution were determined using neutron diffraction with isotopic substitution (NDIS) combined with modelling of the measured structure factors using Empirical Potential Structure Refinement (EPSR). Strongly directional local hydration was observed in the polar regimes of the dizwitterions with 48-52 water molecules shared between dizwitterion molecules in a first shell water network around each zwitterion pair. Overall, the double zwitterions were highly hydrated, providing experimental evidence in support of the potential formation of protein-resistant hydration layers at zwitterion-water interfaces.

New generation of supramolecular mixtures: Characterization and solubilization studies.

In this work, a series of novel low melting mixtures (LMM) based on cyclodextrins (CD) and levulinic acid and inspired by the deep eutectic solvents (DES), were prepared. These supramolecular mixtures are the first reported CD-based mixtures that are liquid at room temperature. Density, viscosity and rheological measurements as well as differential scanning calorimetry and thermogravimetric analysis were performed to characterize these new LMM. Nuclear magnetic resonance (NMR) spectroscopy was used to monitor their stability. Furthermore, their ability to solubilize trans-anethole (AN) and related essentials oils were evaluated by static headspace-gas chromatography (SH-GC), in comparison with water. AN was up to 1300 times more soluble in the CD-based LMM than in water. Finally, multiple headspace extraction (MHE) was used to monitor the release of AN from these LMM. After 10 extractions, 20 to 40% of AN was released from the studied LMM, while 70% was released from water. The new CD-based LMM have potential applications for solubilization and delivery of poorly soluble drugs.

Experiência dos pais em unidade neonatal: implicações para a qualidade da assistência em enfermagem / Parents' experience in a neonatal unit: implications for the quality of nursing care

A chegada de um filho representa para para os pais um momento de muitas expectativas, mas quando ocorre alguma intercorrência de saúde durante a gestação e/ou nascimento os pais passam a conviver com sentimentos opostos à alegria inicial e apresentam dificuldade para lidar com a situação. Objetivo: conhecer a experiência dos pais no processo de internação em Unidade Neonatal em relação à assistência prestada pela equipe de enfermagem. Método: Trata-se de uma pesquisa descritiva com abordagem qualitativa, realizada na Unidade Neonatal de um Hospital Universitário do interior do Rio Grande do Sul, no período de maio a novembro de 2018. A coleta de dados foi realizada por meio de entrevistas, utilizando a técnica do incidente crítico. Os participantes do estudo foram 18 pais que estavam com seus filhos internados por 20 dias ou mais e que tinham planos de alta hospitalar. A análise de conteúdo foi a técnica empregada para análise dos dados. Resultados e Discussão: As entrevistas permitiram caracterizar 43 incidentes críticos que, após análise, originaram três categorias: Ambiência na Unidade Neonatal; Ações de Humanização na Unidade Neonatal e Segurança do Paciente na Unidade Neonatal. A primeira categoria foi dividida em duas subcategorias: Interação entre a equipe de enfermagem e os pais e O cuidado da equipe de enfermagem com os bebês na percepção dos pais. Nesta categoria, as experiências contadas refletem ações desenvolvidas pelos profissionais de enfermagem que possibilitam a equipe de enfermagem fortalecer o vínculo com os pais e criar um espaço de interações que os auxiliam no processo de internação de seus filhos. Em relação a percepção acerca dos cuidados oferecidos pela equipe de enfermagem aos filhos, as experiências mais vivenciadas pelos pais envolvem: o cuidado humanizado, a minimização da visualização dos dispositivos utilizados pelos bebês durante a internação e a comunicação entre a equipe de enfermagem e os pais. A segunda categoria versa sobre as ações de humanização que são realizadas através de projetos específicos na unidade neonatal. Observa-se que os projetos necessitam de reformulação para uniformizar sua implementação e execução e assim facilitar a compreensão de seus objetivos e benefícios. A última categoria, versa sobre a temática da Segurança do Paciente, uma categoria emergente, criada a partir das experiências contadas pelos pais que envolveram a temática. Considerações Finais: Compreende-se que, neste aspecto, há necessidade de capacitações e discussões mais efetivas com a equipe para a resolução das fragilidades referentes a segurança dos bebês. Considera-se que conhecer as experiências dos pais é uma estratégia importante para avaliar a qualidade da assistência da equipe de enfermagem da acerca dos cuidados oferecidos aos bebês e seus pais. Assim, pode-se dizer que a assistência oferecida pela equipe de enfermagem nesta unidade possui elementos que a caracterizam como humana, carinhosa e afetiva, atributos desejáveis num ambiente norteado pela qualidade, tanto para os bebês como para seus pais. Além disto, acredita-se que, em muitos momentos, esta assistência torna as experiências dos pais com a internação de seus filhos na Unidade Neonatal menos traumática.

The arrival of a child represents a moment of expectation for the parents, but when there is an intercurrence of health during the gestation and / or birth, the parents come to live with feelings that are opposed to the initial joy and present difficulties to deal with situation. Objective: to know the experience of the parents in the process of hospitalization in Neonatal Unit in relation to the assistance provided by the nursing team. Method: This is a descriptive research with a qualitative approach, carried out at the Neonatal Unit of a University Hospital in the interior of Rio Grande do Sul from May to November 2018. The data collection was performed through interviews using the technique of the critical incident. The study participants were 18 parents who were with their children hospitalized for 20 days or more and who had plans for hospital discharge. The content analysis was the technique used to analyze the data. Results and Discussion: The interviews allowed to characterize 43 critical incidents that, after analysis, originated three categories: the Environment in the Neonatal Unit; Actions of Humanization in the Neonatal Unit and Patient Safety in the Neonatal Unit. The first category was divided into two subcategories: Interaction between the nursing team and the parents and Care of the nursing team with the babies in the perception of the parents. In this category, the experiences told reflect actions developed by the nursing professionals that enable the nursing staff to strengthen the bond with the parents and to create a space of interactions that help them in the process of hospitalization of their children. In relation to the perception about the care offered by the nursing team to the children, the experiences most experienced by the parents involve: the humanized care, the minimization of the visualization of the devices used by the babies during the hospitalization and the communication between the nursing team and the parents . The second category deals with the humanization actions that are carried out through specific projects in the neonatal unit. It is observed that the projects need reformulation to standardize its implementation and execution and thus facilitate the understanding of its objectives and benefits. The last category deals with the theme of Patient Safety, an emerging category, created from the experiences told by the parents who involved the theme. It is understood that, in this regard, there is a need for more effective training and discussions with the team to resolve the fragilities concerning the safety of babies. Final considerations: It is considered that knowing the experiences of the parents is an important strategy to evaluate the quality of care of the nursing team about the care offered to the babies and their parents. Thus, it can be said that the assistance offered by the nursing team in this unit has elements that characterize it as human, caring and affective, desirable attributes in an environment guided by quality, both for the babies and their parents. In addition, it is believed that, at many times, this assistance makes the experiences of parents with the hospitalization of their children in the Neonatal Unit less traumatic.

A comparison of choline:urea and choline:oxalic acid deep eutectic solvents at 338 K.

1:2 choline chloride:urea and 1:1 choline chloride:oxalic acid deep eutectic solvents are compared at 338 K using liquid-phase neutron diffraction with H/D isotopic substitution to obtain differential neutron scattering cross sections and fitting of models to the experimental data using Empirical Potential Structure Refinement. In comparison to the previously reported study of choline chloride:urea at 303 K, we observed significant weakening and lengthening of choline-OH⋯Cl- and choline-OH⋯hydrogen-bond acceptor correlations.

Frustrated Lewis pairs in ionic liquids and molecular solvents - a neutron scattering and NMR study of encounter complexes.

The presence of the weakly-associated encounter complex in the model frustrated Lewis pair solution (FLP): tris(tert-butyl)phosphine (P(tBu)3) and tris(pentafluorophenyl)borane (BCF) in benzene, was confirmed via PB correlation analysis from neutron scattering data. On average, ca. 5% of dissolved FLP components were in the associated state. NMR spectra of the FLP in benzene gave no evidence of such association, in agreement with earlier reports and the transient nature of the encounter complex. In contrast, the corresponding FLP solution in the ionic liquid, 1-decyl-3-methylimidazolium bistriflamide, [C10mim][NTf2], generated NMR signals that can be attributed to formation of encounter complexes involving over 20% of the dissolved species. The low diffusivity characteristics of ionic liquids is suggested to enhance high populations of encounter complex. The FLP in the ionic liquid solution retained its ability to split hydrogen.

LCST Phase Behavior and Complexation with Water of an Ionic Liquid Incorporating the 5-Phenyltetrazolate Anion.

The use of 5-phenyltetrazole, a bioisostere of benzoic acid, as an anion source to prepare an ionic liquid is described for the first time. Tetrabutylphosphonium 5-phenyltetrazolate undergoes phase separation from water with lower critical solution temperature phase behavior, in contrast to completely water miscible tetrabutylphosphonium benzoate, and also exhibits strong complexation with water with both eutectic and peritectic behavior that has not previously been observed in ionic liquid+water systems. The anhydrous and trihydrate salts were isolated and characterized by single crystal X-ray diffraction.

Effect of unsaturation on the absorption of ethane and ethylene in imidazolium-based ionic liquids.

The influence of the presence of imidazolium side chain unsaturation on the solubility of ethane and ethylene was studied in three ionic liquids: 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide-saturated alkyl side-chain in the cation; 1-methyl-3-(buten-3-yl)imidazolium bis(trifluorosulfonyl)imide-double bond in the side-chain of the cation; and 1-methyl-3-benzylimidazolium bis(trifluorosulfonyl)imide-benzyl group in the side-chain of the cation. The solubility of both gases decreases when the side-chain of the cations is functionalized with an unsaturated group. This can be explained by a less favorable enthalpy of solvation. The difference of solubility between ethane and ethylene can be explained from a balance of enthalpic and entropic factors: for the ionic liquid with the saturated alkyl side-chain and the benzyl-substituted side-chain, it is the favorable entropy of solvation that explains the larger ethylene solubility, whereas in the case of the saturated side-chain, it is the more favorable enthalpy of solvation. Molecular simulation allowed the identification of the mechanisms of solvation and the preferential solvation sites for each gas in the different ionic liquids. Simulations have shown that the entropy of solvation is more favorable when the presence of the gas weakens the cation-anion interactions or when the gas can be solvated near different sites of the ionic liquid.

Stimuli-responsive magnetic nanoparticles for monoclonal antibody purification.

Monoclonal antibodies (mAbs) are important therapeutic proteins. One of the challenges facing large-scale production of monoclonal antibodies is the capacity bottleneck in downstream processing, which can be circumvented by using magnetic stimuli-responsive polymer nanoparticles. In this work, stimuli-responsive magnetic particles composed of a magnetic poly(methyl methacrylate) core with a poly(N-isopropylacrylamide-co-acrylic acid) (P(NIPAM-co-AA)) shell cross-linked with N, N'-methylenebisacrylamide were prepared by miniemulsion polymerization. The particles were shown to have an average hydrodynamic diameter of 317 nm at 18°C, which decreased to 277 nm at 41°C due to the collapse of the thermo-responsive shell. The particles were superparamagnetic in behavior and exhibited a saturation magnetization of 12.6 emu/g. Subsequently, we evaluated the potential of these negatively charged stimuli-responsive magnetic particles in the purification of a monoclonal antibody from a diafiltered CHO cell culture supernatant by cation exchange. The adsorption of antibodies onto P(NIPAM-co-AA)-coated nanoparticles was highly selective and allowed for the recovery of approximately 94% of the mAb. Different elution strategies were employed providing highly pure mAb fractions with host cell protein (HCP) removal greater than 98%. By exploring the stimuli-responsive properties of the particles, shorter magnetic separation times were possible without significant differences in product yield and purity.

Preparation and characterization of low dispersity anionic multiresponsive core-shell polymer nanoparticles.

We prepared anionic multistimuli responsive core-shell polymer nanoparticles with very low size dispersity. By using either acrylic acid (AA) or methacrylic acid (MA) as a comonomer in the poly(N-isopropyl acrylamide) (PNIPAM) shell, we are able to change the distribution of negative charges in the nanoparticle shell. The particle size, volume phase transition temperature, and aggregation state can be modulated using temperature, pH, or ionic strength, providing a very versatile platform for applications in sensors, medical diagnostics, environmental remediation, etc. The nanoparticles have a glassy poly(methyl methacrylate) (PMMA) core of ca. 40 nm radius and a cross-linked PNIPAM anionic shell with either AA or MA comonomers. The particles, p(N-AA) and p(MA-N), respectively, have the same total charge but different charge distributions. While the p(MA-N) particles have the negative charges preferentially distributed toward the inner shell, in the case of the p(N-AA) particles the charge extends more to the particle outer shell. The volume phase transition temperature (T(VPT)) of the particles is affected by the charge distribution and can be fine-tuned by controlling the electrostatic repulsion on the particle shell (using pH and ionic strength). By suppressing the particle charge we can also induce temperature-driven particle aggregation.

DNA hybridization in thermoresponsive polymer nanoparticles.

We achieve very high hybridization efficiencies by using a new method to immobilize DNA strands on the surface of thermoresponsive polymer nanoparticles. Hybridization efficiencies of about 70 % are obtained between the DNA immobilized in the particles and a complementary strand in solution, even at very low ionic strengths (1 mM). The polymer nanoparticles have a glassy poly(methylmethacrylate) (PMMA) core and a thermoresponsive shell of poly(N-isopropylacrylamide) (PNIPAM) containing positive charges. After a DNA strand labeled with a fluorescence probe is loaded onto the particles at room temperature, the temperature is increased above the volume phase transition temperature of the PNIPAM shell, TVPT approximately 28 degrees C. The collapse of the particle shell immobilizes the DNA while maintaining its availability for hybridization with a complementary strand. Förster resonance energy transfer (FRET) is used to detect the hybridization with a complementary DNA strand labeled with a FRET acceptor probe.

Canopy gap colonization in the Atlantic Montane Rain Forest

In the Atlantic Montane Rain Forest of South-eastern Brazil, a study was carried out to describe and evaluate canopy gap colonization. Gap composition by herb species was assessed through their soil coverage and woody species by measuring and identifying all individuals taller than one meter. Gap structure (gap size, number and diameter of treefalls), topographic position and surrounding vegetation were also measured. Two genera of Marantaceae were markedly frequent and abundant inside gaps. The more abundant and frequent woody species were shade tolerant. Species-rich families found inside gaps did not differ from the forest as a whole. Results revealed that direct and indirect influences of topography were important to determine gap composition of woody species. Evidently gap colonization had a considerable influence of topography and pre-established individuals besides variables of gap structure.

Na Floresta Pluvial Atlântica Montana do Sudeste Brasileiro, foi realizado um estudo para descrever e avaliar a colonização de clareiras. A composição de clareiras foi levantada através da cobertura do solo para as espécies herbáceas enquanto que todos os indivíduos lenhosos maiores que um metro de altura foram mensurados e identificados. Também foram coletadas informações sobre a estrutura das clareiras (área da clareira, número e diâmetro das quedas), posição topográfica e vegetação circundante. Dois gêneros de Marantaceae apresentaram considerável freqüência e abundância nas clareiras. As espécies lenhosas mais freqüentes e abundantes pertenceram ao grupo não-pioneiro e as famílias mais ricas encontradas nas clareiras não diferiram quando comparado à floresta como um todo. Como para as variáveis do estrato herbáceo e da vegetação circundante, os resultados revelaram que efeitos diretos e indiretos da topografia são importantes na determinação da composição interna de clareiras por espécies lenhosas. Estes resultados sugerem que a colonização de clareiras é influenciada não apenas pelas variáveis de estrutura, mas também pela posição topográfica e pelos indivíduos pré-estabelecidos.